Periodontal disease initiation and progression occurs as a consequence of the host immune inflammatory response to oral pathogens. Tristetraprolin (TTP) is a zinc finger protein that binds to the ARE of cytokine mRNAs and enhances degradation of the mRNA. TTP is phosphorylated by the p38-MK2 pathway and may serve as a general mechanism of cytokine mRNA regulation. The objective of this application is to determine how TTP and the MK2 pathway modify periodontal disease initiation and progression. Experimental models of periodontitis where TTP is over-expressed show a reduction of pro-inflammatory proteins and reduced amount of LPS-induced alveolar bone loss. Preliminary data for this proposal indicates that mutant mice lacking TTP display an increased amount of periodontal bone loss compared with wild type littermates. The aims for this proposal are 1) to determine the role of TTP expression/phosphorylation status directs local inflammatory cytokine expression in periodontal disease progression, 2) to determine if TTP will determine the extent of inflammation and alveolar bone loss in experimental models of periodontal disease, and 3) measure TTP expression and phosphorylation status in human periodontal disease progression. These studies will establish the role of a key RNA binding protein in experimental models and human periodontitis. Using genetic models lacking TTP or the key kinase that modulates TTP function, MK2, definitive data relative to TTP biology related to periodontal disease will be gained. Foundation and translational significance of mRNA stability will provide insight into the potential of these proteins to be targeted for future studies that will modify innate immune cytokine expression for therapeutic benefit in the management of chronic periodontitis. PUBLIC HEALTH RELEVANCE: Periodontal disease progression occurs as a consequence of the host immune inflammatory response to oral pathogens. These studies will establish the role of RNA binding proteins needed to mediate inflammatory cytokine mRNA stability. Progress in understanding the role of posttranscriptional cytokine regulation in periodontal inflammation and bone loss may yield new possibilities for treatment of periodontal diseases.